[WEC] LMP Future Regulations (was Le Mans EVO rules - now hypercar rules)

[gwyllion]

In Petit Le Mans Baretzky made some comments on a potential performance cut for diesel engines, which this week has been confirmed by the ACO: http://forums.fourtitude.com/entry.p...aretzky-s-Take

[AGD]

Originally Posted by deggis

You don't see the forest for the trees...? Audi's wins in 2008 pretty much required Peugeot to screwup things by themselves or have other technical mishaps due the performance difference.

How is it justified to give an advantage to the team that won? At that point, it was almost expected that Peugeot would screw up regularly even if they had the faster car so I think Audi was still the favorite to win whether they had max pace or not. That mindset still continues to this day for some, but it really only seems to apply at Le Mans. It's Audi who screws up everywhere else now.

Originally Posted by JAG

Has anyone done calculations as to what 7% less power would relate to in track time at Le Mans.

On the face of it, it seems quite a chunk of time but in reality it's unlikey to amount to more than a couple of seconds.

It's hard to say because Audi and Peugeot will undoubtedly do some R&D to get some of the lost performance back one way or another. The funny thing is that everyone (almost) gets excited about the diesels getting neutered, but then the next year we are right back where we started because of the work the factory teams are able to do with their resources. Somehow the rules get blamed for this. Go figure. We would hear the old general slogan of "I don't know where or how the factory teams are cheating, but clearly they are cheating if they are able to beat jalopy X so ban them," but now we get the specific whines about diesel since that is what the factory teams run. The fuel that allows Audi and Peugeot to have the "unfair" advantage is not diesel, it is money. I don't know how it is lost on so many race fans that money buys speed.

[gregtummer]

Originally Posted by AGD

How is it justified to give an advantage to the team that won? At that point, it was almost expected that Peugeot would screw up regularly even if they had the faster car so I think Audi was still the favorite to win whether they had max pace or not. That mindset still continues to this day for some, but it really only seems to apply at Le Mans. It's Audi who screws up everywhere else now.



It's hard to say because Audi and Peugeot will undoubtedly do some R&D to get some of the lost performance back one way or another. The funny thing is that everyone (almost) gets excited about the diesels getting neutered, but then the next year we are right back where we started because of the work the factory teams are able to do with their resources. Somehow the rules get blamed for this. Go figure. We would hear the old general slogan of "I don't know where or how the factory teams are cheating, but clearly they are cheating if they are able to beat jalopy X so ban them," but now we get the specific whines about diesel since that is what the factory teams run. The fuel that allows Audi and Peugeot to have the "unfair" advantage is not diesel, it is money. I don't know how it is lost on so many race fans that money buys speed.

Yes. Now they will just gain back all the time through aerodynamics.

[JAG]

Originally Posted by AGD

The fuel that allows Audi and Peugeot to have the "unfair" advantage is not diesel, it is money. I don't know how it is lost on so many race fans that money buys speed.

It isn't, but restrictors are an artificial intervention by rules makers. If they get their sums wrong they could make the diesels the slowest P1's in the field even with Audi and Peugeot's budget.

The ACO have dyno data for all the major players, they are no longer making adjustments based on lap times, they only analyse engine performance. Neither are they intent on equalising everyone, they are ensuring each engine configeration has equal potential, that applies to 3.4 V8 vs 2.0T as it does petrol vs diesel.

Once everyone is starting on an equal footing then, and only then, is it acceptable for manufactuers money to buy speed. I too think the petrol/diesel equivalence has been overplayed but as the years progressed the likes of Rebellion and Oak have made developments and gained reliabity (to finish first, you must first finish) yet haven't been given a glimpse of encouragement by closing the gap.

The HPD had a blistering Sebring and I think would still be the class of the petrol field if it was rolled out at Zhuhai, but the petrol field is improving and giving them a little help isn't going turn the field upside down.

[chernaudi]

For the record, Mike posted on his Facebook page that a 6-7% power reduction equals roughly 20 or so bhp. Also, the turbocharger boost reduction isn't to reduce power as to tailor that to the smaller air restrictor to improve reliability.

[AGD]

Originally Posted by JAG

Once everyone is starting on an equal footing then, and only then, is it acceptable for manufactuers money to buy speed. I too think the petrol/diesel equivalence has been overplayed but as the years progressed the likes of Rebellion and Oak have made developments and gained reliabity (to finish first, you must first finish) yet haven't been given a glimpse of encouragement by closing the gap.

The HPD had a blistering Sebring and I think would still be the class of the petrol field if it was rolled out at Zhuhai, but the petrol field is improving and giving them a little help isn't going turn the field upside down.

I understand what you're trying to say and it is nice that you don't sugar coat the intention, but I still don't agree with that ideology. The forgotten thing is that if diesel has such a theoretical advantage, why don't these teams just switch to diesel? It's not like this is the first year Audi and Peugeot have run the diesels. We're one race away from having 6 full seasons of diesels plus the Taurus if you want to count that. Instead of complaining, just go back to the shop and build a better mousetrap so to speak. If the answer is that they don't have the resources to do it, well, we already have a solution to that in endurance sports car racing: LMP2.

Trying to balance stuff is futile, especially when the "haves" are the only ones trying to run a technology, and charity regulations are not what professional sports are about. The results may stay the same at the end of the day, but when I watch a race, I want to see the best that each team can bring to the track. Let's see all the different ideas. Some ideas and some levels of execution are just better than others. As a fan, I can look at the results and judge each team's results within their context. Don't try to meddle with the natural flow of that or you end up with what the IRL has on it's hands. A series that has supposedly "spectacular" racing with endless potential winners that ends up getting ~100,000 viewers/0.1 rating in a good time slot!

[JAG]

You're talking about BoP, I'm talking about giving all engine configerations an equal starting point, before letting manufactuers pour as many resources into the program as they so wish.

If you want a free engine formula that's fine, but you'd have to ditch restrictors and accept everyone will use small petrol turbo's. If you want to see NA, turbo, petrol, diesel, 4-cylinder, V6, V8, I6 configerations, you need to have restrictors and/or fuel allocations to give them all the potential to be competitive.

[gregtummer]

I hope all this performance balancing goes away starting in 2014.

The rule should be that you use no more than 400 gallons (or whatever) of fuel at Le Mans. Other than that, do whatever you want (for the most part). And then use 1/4 of that fuel for the 6 Hour races.

Then they just have to make sure to get the energy equivalency between the different fuels right.

[AGD]

Originally Posted by JAG

You're talking about BoP, I'm talking about giving all engine configerations an equal starting point, before letting manufactuers pour as many resources into the program as they so wish.

If you want a free engine formula that's fine, but you'd have to ditch restrictors and accept everyone will use small petrol turbo's. If you want to see NA, turbo, petrol, diesel, 4-cylinder, V6, V8, I6 configerations, you need to have restrictors and/or fuel allocations to give them all the potential to be competitive.

Fine, so be it. It's better than a false sense of open competition. I think the marketers would provide for some differentiation anyway. Besides, if it wasn't for Audi and Peugeot, all we would be seeing in P1 right now are NA 3.4L V8s. Oh, and the AMR I6 maybe, ha. And the AER MZR-R, but who wants to tackle the isobutanol equalization dilemma? Is nobody fighting for it and the sham rules petrol has over it that gives petrol an unfair advantage?

As for the balancing of technologies, it's easy to say you're making adjustments on the basis of technology when reality is that the adjustments are a straight BoP when the dominators are the only ones running a technology. Just as we would hear the same things if Audi and Peugeot were the only ones with gas turbos if that were the case. Yeah, yeah, data loggers, etc. And I live in Hawaii in an igloo. The data loggers probably tell the ACO how much BoP they can do without seriously ****ing off the factory teams.

[henk4]

Originally Posted by chernaudi

For the record, Mike posted on his Facebook page that a 6-7% power reduction equals roughly 20 or so bhp. Also, the turbocharger boost reduction isn't to reduce power as to tailor that to the smaller air restrictor to improve reliability.

Is there anybody here who can clarify whether a 7% power reduction via restrictors will also result in 7% less torque?

[MitchZ06]

Depends on engine mapping as to whether or not torque will drop that much.

[henk4]

Originally Posted by MitchZ06

Depends on engine mapping as to whether or not torque will drop that much.

that I understand, and as we all know the diesels have a big advantage in the torque department, is the proposed reduction going to be as effective as one might think on first glance? Does anybody know how the torque value this year of the grandfathered Oreca 908 compared to the figure for the factory cars?

[MitchZ06]

I don't sorry but others might, it might be that this 7% reduction makes torque levels even between petrol and diesel disregarding hp?

[gwyllion]

Originally Posted by chernaudi

For the record, Mike posted on his Facebook page that a 6-7% power reduction equals roughly 20 or so bhp. Also, the turbocharger boost reduction isn't to reduce power as to tailor that to the smaller air restrictor to improve reliability.

That number does not seem right. The official power output of the 908 V8 HDI engine is 550 hp (see here) and Audi claims over 540 hp (see here); in practice the number is probably close to 600 hp. 6.7% x 550 hp = 37 hp and 6.7% x 600 hp = 40 hp. That is a significant power reduction.

Originally Posted by henk4

Is there anybody here who can clarify whether a 7% power reduction via restrictors will also result in 7% less torque?

The (absolute) boost pressure of diesel engines will go down from 3000 mbar to 2800 mbar, which is a 6.7% reduction. That means ~7% less air volume in the engine and hence ~7% less torque. Of course they can still inject more diesel in the engine to regain some torque and power, with more (visible) smoke as result. However, with some more engine development (compression ratio, combustion chamber, fuel injection/pressure, friction loss reduction, etc.) they can (partially) compensate for the rule change.

[henk4]

Originally Posted by gwyllion

That number does not seem right. The official power output of the 908 V8 HDI engine is 550 hp (see here) and Audi claims over 540 hp (see here); in practice the number is probably close to 600 hp. 6.7% x 550 hp = 37 hp and 6.7% x 600 hp = 40 hp. That is a significant power reduction.
The (absolute) boost pressure of diesel engines will go down from 3000 mbar to 2800 mbar, which is a 6.7% reduction. That means ~7% less air volume in the engine and hence ~7% less torque. Of course they can still inject more diesel in the engine to regain some torque and power, with more (visible) smoke as result. However, with some more engine development (compression ratio, combustion chamber, fuel injection/pressure, friction loss reduction, etc.) they can (partially) compensate for the rule change.

so the torque curve will be seven % lower over the whole rev range?

[gwyllion]

Originally Posted by henk4

that I understand, and as we all know the diesels have a big advantage in the torque department, is the proposed reduction going to be as effective as one might think on first glance? Does anybody know how the torque value this year of the grandfathered Oreca 908 compared to the figure for the factory cars?

Audi claims "over 900 Nm" for the R18 (see here), while Oreca states "around 950 Nm" for the grandfathered 908 (see here). Of course, Audi is underquoting their torque number, so it will probably be in above 1000 Nm.

Note that in the beginning of the season the Oreca 908 weighed 30 kg more than the factory diesel (930 vs 900 kg) and from Le Mans onwards it weighed 915 kg.

[henk4]

Originally Posted by gwyllion

Audi claims "over 900 Nm" for the R18 (see here), while Oreca states "around 950 Nm" for the grandfathered 908 (see here). Of course, Audi is underquoting their torque number, so it will probably be in above 1000 Nm.

Note that in the beginning of the season the Oreca 908 weighed 30 kg more than the factory diesel (930 vs 900 kg) and from Le Mans onwards it weighed 915 kg.

well, can we believe Audi, when they call their engine a 3.6 liter powertrain

so we still don't know whether the 5.5 liter oreca engine has the same torque amount as the 908 3.7 litre...it looks like it but still.

[gwyllion]

Originally Posted by henk4

well, can we believe Audi, when they call their engine a 3.6 liter powertrain

Someone screwed up that website because in the engine technical data they write "cubic capacity = 3,700 ccm".

[henk4]

Originally Posted by gwyllion

Someone screwed up that website because in the engine technical data they write "cubic capacity = 3,700 ccm".

I saw that too, but for that you have to dig.....and people generally don't like digging further.

[gwyllion]

Originally Posted by henk4

I saw that too, but for that you have to dig.....and people generally don't like digging further.

I only use the Audi USA website, because the international/German website does not give detailed technical specifications about the R18: http://www.audi.com/com/brand/en/exp...i_r18_tdi.html

[henk4]

Originally Posted by gwyllion

I only use the Audi USA website, because the international/German website does not give detailed technical specifications about the R18: http://www.audi.com/com/brand/en/exp...i_r18_tdi.html

I think both websites will carefully refrain from posting the real essentials....

[ubrben]

Originally Posted by henk4

Is there anybody here who can clarify whether a 7% power reduction via restrictors will also result in 7% less torque?

For me torque is a side issue. Torque on it's own is meaningless because a diesel generates massive torque at low RPM. When you factor this up to the torque at the driven wheels it's less of a gap than the raw numbers for the engine alone.

The reason Audi and Peugeot are so fast is a pure horsepower advantage. They can run Le Mans a faster straightline speeds than the petrol cars, while at the same time carrying more downforce.

When the diesels are accelerating off the chicanes faster than the other cars that's in a traction limited situation - it's not power or torque limited. The only way of increasing the traction limit is to run more rear weight (or weight transfer) or to add downforce. The diesels can add downforce because they have the HP to deal with the extra drag.

When we talk about torque it's probably more relevant to talk about the shape of the curve - you do get a medium speed acceleration gain (for a fixed number of gear ratios) with a flatter torque curve - but this can also be explained as a higher average HP over a given rev range.

Incidentally this comment about flatter power/torque curves is equally relevant for turbo petrol vs. NA petrol. Witness the issues earlier in the season trying to get a decent balance between the HPD turbo engine and the Atmo Nissan and Judd in LMP2. In that case the atmo guys initially won the argument.

Horsepower dictate the straightline speed vs. downforce level tradeoff and for a car with a hugh aero potential it's vital to look at the HP. Inicdentally if you look at GT sector data for ALMS you can see the medium speed acceleration advantage of a wider torque curve by looking at the Corvette on a short straight like the S/F at Mosport and Laguna vs. a long straight like the back straight at Mosport or Road Atlanta. So I'm not denying that it doesn't have an effect, but it's second order compared with HP in the diesel discussion.

Ben

[gwyllion]

Take a look at these "official" data about engine performance:

• Judd DB V8: peak power = 540 bhp @ 10000 rpm, peak torque = 406 Nm @ 9000 rpm (see here)
• Audi V6 TDI: peak power = 540+ hp (assumption: @ 4500 rpm), peak torque = 900+ Nm (see here)

The petrol engine will have a final gear ratio that is 2.22 times (= 10000/4500) than that of the diesel engine. Hence, the peak torque at the wheels is relatively 2.22 times more: 406 Nm x 2.22 = 900 Nm! So on paper the turbo diesel and NA petrol engines produce similar peak torque at the wheels.

However, as ubrben explained, peak torque is meaningless. A turbo (diesel) engine shines because its torque is available over a much larger rev range than a normally aspirated petrol engine.

Also see Mike's calculations of the average torque of both engine configurations: http://www.mulsannescorner.com/newsmay11.html (5/16/2011 entry). Note that these calculations talk about torque at the flywheel, not at the wheels, so they don't take into account the gearing.

On top of that in 2011 diesels had a big power advantage, because in practice the engines produced close to 600 hp instead of the 540-550 hp that Audi and Peugeot claimed. With the 2012 rule change, this advantage will be reduced: 600 hp - 7% = 560 hp.

[ubrben]

Originally Posted by gwyllion

However, as ubrben explained, peak torque is meaningless. A turbo (diesel) engine shines because its torque is available over a much larger rev range than a normally aspirated petrol engine. See Mike's calculations of the average torque of both engine configurations: http://www.mulsannescorner.com/newsmay11.html

But for a given peak HP a turbo is better than an atmo and a larger capacity engine is better than a small capacity. The diesel have historically had more capacity and turbos....

You have an 3.4 L atmo petrol V8 vs. a 3.7L turbo Diesel. It's hardly a shocker that the diesel has more HP. Would it be fair to have 3.4L turbo petrol vs. Atmo???

Ben

[MitchZ06]

Ditch the petrol engine rules and make them even with diesel and we'll see who is fastest...